Problem: $J$ $K$ $L$ If: $ KL = 4x + 3$, $ JK = 4x + 2$, and $ JL = 45$, Find $KL$.
From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {4x + 2} + {4x + 3} = {45}$ Combine like terms: $ 8x + 5 = {45}$ Subtract $5$ from both sides: $ 8x = 40$ Divide both sides by $8$ to find $x$ $ x = 5$ Substitute $5$ for $x$ in the expression that was given for $KL$ $ KL = 4({5}) + 3$ Simplify: $ {KL = 20 + 3}$ Simplify to find ${KL}$ : $ {KL = 23}$